Comparison of strategies to efficiently combine repeated urine samples in biomarker-based studies

Details

• Alternative Title:
  Environ Res
• Personal Author:
  Philippat, Claire ; Calafat, Antonia M.
• Description:
  Background:
  
  In biomarker-based studies, collecting repeated biospecimens per participant can decrease measurement error, particularly for biomarkers displaying high within-subject variability. Guidelines to combine such repeated biospecimens do not exist.
  
  Aims:
  
  To compare the efficiency of several designs relying on repeated biospecimens to estimate exposure over 7 days.
  
  Methods:
  
  We quantified triclosan and bisphenol A (BPA) in all urine voids (N=427) collected over seven days from eight individuals. We estimated the volume-weighted concentrations for all urine samples collected during a week and compared these gold standards with the concentrations obtained for equal-volume pools (standardized or not for urine dilution), unequal-volume pools (based on sample volume or creatinine concentration), and for the mean of the creatinine-standardized concentrations measured in each spot sample.
  
  Results:
  
  For both chemicals, correlations with gold standards were similar for equal- and unequal-volume pooling designs. Only for BPA, correlation coefficients were markedly lower after standardization for specific gravity or creatinine of concentrations estimated in equal-volume pools. Averaging BPA creatinine-standardized concentrations measured in each spot sample led also to lower correlations with gold standards compared to those obtained for unstandardized pooling designs.
  
  Conclusion:
  
  For BPA and triclosan, considering individual urine sample volume or creatinine concentrations when pooling is unnecessary because equal-volume pool adequately estimates concentrations in gold standards. Standardization for specific gravity or creatinine of the concentrations assessed in equal-volume pool as well as averaging creatinine-standardized concentrations measured in each individual spot sample are not suitable for BPA. These results provide a practical framework on how to combine repeated biospecimens in epidemiological studies.
  
  
• Subjects:
  Article Benzhydryl Compounds Biomarkers Bisphenol A Humans Measurement Error Pooling Designs Repeated Biospecimens Triclosan
• Source:
  Environ Res. 192:110275
• Pubmed ID:
  33022216
• Pubmed Central ID:
  PMC7879377
• Document Type:
  Journal Article
• Funding:
  CC999999/ImCDC/Intramural CDC HHSUnited States/
• Volume:
  192
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha256:61e237dbfef2037f76f1af6dbd24c313d8b94fc92b8c3b78f1eb41e9005240b1
• Download URL:
  https://stacks.cdc.gov/view/cdc/103500/cdc_103500_DS1.pdf
• File Type:
  [PDF - 633.42 KB ]